140 research outputs found
Catalytic intramolecular hydroamination of aminoallenes using titanium and tantalum complexes of sterically encumbered chiral sulfonamides
Catalysis using earth abundant metals is an important goal due to the relative scarcity and expense of precious metal catalysts. It would be even more beneficial to use earth abundant catalysts for the synthesis of common pharmaceutical structural motifs such as pyrrolidine and pyridine. Thus, developing titanium catalysts for asymmetric ring closing hydroamination is a valuable goal. In this work, four sterically encumbered chiral sulfonamides derived from naturally occurring amino acids were prepared. These compounds undergo protonolysis reactions with Ti(NMeâ)â or Ta(NMeâ)â
to give monomeric complexes as determined by both DOSY NMR and X-ray crystallography. The resulting complexes are active for the ring closing hydroamination hepta-4,5-dienylamine to give a mixture of tetrahydropyridine and pyrrolidine products. However, the titanium complexes convert 6-methylhepta-4,5-dienylamine exclusively to 2-(2-methylpropenyl)pyrrolidine in higher enantioselectivity than those previously reported, with enantiomeric excesses ranging from 18â24%. The corresponding tantalum complexes were more selective with enantiomeric excesses ranging from 33â39%
Rotation Curves in z~1-2 Star-Forming Disks: Evidence for Cored Dark Matter Distributions
We report high-quality, Hα or CO rotation curves (RCs) to several R e for 41 large, massive, star-forming disk galaxies (SFGs) across the peak of cosmic galaxy evolution (z ~ 0.67-2.45), taken with the ESO-VLT, the LBT and IRAM-NOEMA. Most RC41 SFGs have reflection-symmetric RCs plausibly described by equilibrium dynamics. We fit the major axis position-velocity cuts using beam-convolved forward modeling generated in three dimensions, with models that include a bulge and turbulent disk component embedded in a dark matter (DM) halo. We include priors for stellar and molecular gas masses, optical light effective radii and inclinations, and DM masses from abundance-matching scaling relations. Two-thirds or more of the z ℠1.2 SFGs are baryon dominated within a few R e of typically 5.5 kpc and have DM fractions less than maximal disks (median ). At lower redshift (z < 1.2), that fraction is less than one-third. DM fractions correlate inversely with the baryonic angular momentum parameter, baryonic surface density, and bulge mass. Inferred low DM fractions cannot apply to the entire disk and halo but more plausibly reflect a flattened, or cored, inner DM density distribution. The typical central "DM deficit" in these cores relative to Navarro-Frenk-White (NFW) distributions is ~30% of the bulge mass. The observations are consistent with rapid radial transport of baryons in the first-generation massive gas-rich halos forming globally gravitationally unstable disks and leading to efficient build-up of massive bulges and central black holes. A combination of heating due to dynamical friction and AGN feedback may drive DM out of the initial cusps.This work was supported in part by DFG/DIP grant
STE/1869 2-1/GE 625/17-
In Vitro Pharmacological Characterization of RXFP3 Allosterism: An Example of Probe Dependency
Recent findings suggest that the relaxin-3 neural network may represent a new ascending arousal pathway able to modulate a range of neural circuits including those affecting circadian rhythm and sleep/wake states, spatial and emotional memory, motivation and reward, the response to stress, and feeding and metabolism. Therefore, the relaxin-3 receptor (RXFP3) is a potential therapeutic target for the treatment of various CNS diseases. Here we describe a novel selective RXFP3 receptor positive allosteric modulator (PAM), 3-[3,5-Bis(trifluoromethyl)phenyl]-1-(3,4-dichlorobenzyl)-1-[2-(5-methoxy-1H-indol-3-yl)ethyl]urea (135PAM1). Calcium mobilization and cAMP accumulation assays in cell lines expressing the cloned human RXFP3 receptor show the compound does not directly activate RXFP3 receptor but increases functional responses to amidated relaxin-3 or R3/I5, a chimera of the INSL5 A chain and the Relaxin-3 B chain. 135PAM1 increases calcium mobilization in the presence of relaxin-3NH2 and R3/I5NH2 with pEC50 values of 6.54 (6.46 to 6.64) and 6.07 (5.94 to 6.20), respectively. In the cAMP accumulation assay, 135PAM1 inhibits the CRE response to forskolin with a pIC50 of 6.12 (5.98 to 6.27) in the presence of a probe (10 nM) concentration of relaxin-3NH2. 135PAM1 does not compete for binding with the orthosteric radioligand, [125I] R3I5 (amide), in membranes prepared from cells expressing the cloned human RXFP3 receptor. 135PAM1 is selective for RXFP3 over RXFP4, which also responds to relaxin-3. However, when using the free acid (native) form of relaxin-3 or R3/I5, 135PAM1 doesn't activate RXFP3 indicating that the compound's effect is probe dependent. Thus one can exchange the entire A-chain of the probe peptide while retaining PAM activity, but the state of the probe's c-terminus is crucial to allosteric activity of the PAM. These data demonstrate the existence of an allosteric site for modulation of this GPCR as well as the subtlety of changes in probe molecules that can affect allosteric modulation of RXFP3
The KMOS3D Survey: Demographics and Properties of Galactic Outflows at z=0.6-2.7
We present a census of ionized gas outflows in 599 normal galaxies at redshift 0.6 < z < 2.7, mostly based on integral field spectroscopy of H alpha, [N II], and [S II] line emission. The sample fairly homogeneously covers the main sequence of star-forming galaxies with masses 9.0 < log(M-*/M-circle dot) < 11.7, and probes into the regimes of quiescent galaxies and starburst outliers. About one-third exhibits the high-velocity component indicative of outflows, roughly equally split into winds driven by star formation (SF) and active galactic nuclei (AGNs). The incidence of SF-driven winds correlates mainly with SF properties. These outflows have typical velocities of similar to 450 km s(-1), local electron densities of n(e) similar to 380 cm(-3), modest mass loading factors of similar to 0.1-0.2 at all galaxy masses, and energetics compatible with momentum driving by young stellar populations. The SF-driven winds may escape from log(M-*/M-circle dot) less than or similar to 10.3 galaxies, but substantial mass, momentum, and energy in hotter and colder outflow phases seem required to account for low galaxy formation efficiencies in the low-mass regime. Faster AGN-driven outflows (similar to 1000-2000 km s(-1)) are commonly detected above log(M-*/M-circle dot) similar to 10.7, in up to similar to 75% of log(M-*/M-circle dot) greater than or similar to 11.2 galaxies. The incidence, strength, and velocity of AGN-driven winds strongly correlates with stellar mass and central concentration. Their outflowing ionized gas appears denser (n(e) similar to 1000 cm(-3)), and possibly compressed and shock-excited. These winds have comparable mass loading factors as the SF-driven winds but carry similar to 10 (similar to 50) times more momentum (energy). The results confirm our previous findings of high-duty-cycle, energy-driven outflows powered by AGN above the Schechter mass, which may contribute to SF quenching.E.S.W. and J.T.M. acknowledge
support by the Australian Research Council Center of
Excellence for All Sky Astrophysics in Three Dimensions
(ASTRO 3D), through project number CE170100013. D.J.W.
and M.F. acknowledge the support of the Deutsche Forschungsgemeinschaft via Project ID 3871/1-1 and 3871/1-2.
G.B.B. acknowledges support from the Cosmic Dawn Center,
which is funded by the Danish National Research Foundation
Quantifying neutralising antibody responses against SARS-CoV-2 in dried blood spots (DBS) and paired sera
The ongoing SARS-CoV-2 pandemic was initially managed by non-pharmaceutical interventions such as diagnostic testing, isolation of positive cases, physical distancing and lockdowns. The advent of vaccines has provided crucial protection against SARS-CoV-2. Neutralising antibody (nAb) responses are a key correlate of protection, and therefore measuring nAb responses is essential for monitoring vaccine efficacy. Fingerstick dried blood spots (DBS) are ideal for use in large-scale sero-surveillance because they are inexpensive, offer the option of self-collection and can be transported and stored at ambient temperatures. Such advantages also make DBS appealing to use in resource-limited settings and in potential future pandemics. In this study, nAb responses in sera, venous blood and fingerstick blood stored on filter paper were measured. Samples were collected from SARS-CoV-2 acutely infected individuals, SARS-CoV-2 convalescent individuals and SARS-CoV-2 vaccinated individuals. Good agreement was observed between the nAb responses measured in eluted DBS and paired sera. Stability of nAb responses was also observed in sera stored on filter paper at room temperature for 28Â days. Overall, this study provides support for the use of filter paper as a viable sample collection method to study nAb responses.</p
The thalamus and its subnucleiâa gateway to obsessive-compulsive disorder
Larger thalamic volume has been found in children with obsessive-compulsive disorder (OCD) and children with clinical-level symptoms within the general population. Particular thalamic subregions may drive these differences. The ENIGMA-OCD working group conducted mega- and meta-analyses to study thalamic subregional volume in OCD across the lifespan. Structural T-1-weighted brain magnetic resonance imaging (MRI) scans from 2649 OCD patients and 2774 healthy controls across 29 sites (50 datasets) were processed using the FreeSurfer built-in ThalamicNuclei pipeline to extract five thalamic subregions. Volume measures were harmonized for site effects using ComBat before running separate multiple linear regression models for children, adolescents, and adults to estimate volumetric group differences. All analyses were pre-registered (https://osf.io/73dvy) and adjusted for age, sex and intracranial volume. Unmedicated pediatric OCD patients (<12 years) had larger lateral (d = 0.46), pulvinar (d = 0.33), ventral (d = 0.35) and whole thalamus (d = 0.40) volumes at unadjusted p-values <0.05. Adolescent patients showed no volumetric differences. Adult OCD patients compared with controls had smaller volumes across all subregions (anterior, lateral, pulvinar, medial, and ventral) and smaller whole thalamic volume (d = -0.15 to -0.07) after multiple comparisons correction, mostly driven by medicated patients and associated with symptom severity. The anterior thalamus was also significantly smaller in patients after adjusting for thalamus size. Our results suggest that OCD-related thalamic volume differences are global and not driven by particular subregions and that the direction of effects are driven by both age and medication status
Procalcitonin Is Not a Reliable Biomarker of Bacterial Coinfection in People With Coronavirus Disease 2019 Undergoing Microbiological Investigation at the Time of Hospital Admission
Abstract Admission procalcitonin measurements and microbiology results were available for 1040 hospitalized adults with coronavirus disease 2019 (from 48 902 included in the International Severe Acute Respiratory and Emerging Infections Consortium World Health Organization Clinical Characterisation Protocol UK study). Although procalcitonin was higher in bacterial coinfection, this was neither clinically significant (median [IQR], 0.33 [0.11â1.70] ng/mL vs 0.24 [0.10â0.90] ng/mL) nor diagnostically useful (area under the receiver operating characteristic curve, 0.56 [95% confidence interval, .51â.60]).</jats:p
Implementation of corticosteroids in treating COVID-19 in the ISARIC WHO Clinical Characterisation Protocol UK:prospective observational cohort study
BACKGROUND: Dexamethasone was the first intervention proven to reduce mortality in patients with COVID-19 being treated in hospital. We aimed to evaluate the adoption of corticosteroids in the treatment of COVID-19 in the UK after the RECOVERY trial publication on June 16, 2020, and to identify discrepancies in care. METHODS: We did an audit of clinical implementation of corticosteroids in a prospective, observational, cohort study in 237 UK acute care hospitals between March 16, 2020, and April 14, 2021, restricted to patients aged 18 years or older with proven or high likelihood of COVID-19, who received supplementary oxygen. The primary outcome was administration of dexamethasone, prednisolone, hydrocortisone, or methylprednisolone. This study is registered with ISRCTN, ISRCTN66726260. FINDINGS: Between June 17, 2020, and April 14, 2021, 47â795 (75·2%) of 63â525 of patients on supplementary oxygen received corticosteroids, higher among patients requiring critical care than in those who received ward care (11â185 [86·6%] of 12â909 vs 36â415 [72·4%] of 50â278). Patients 50 years or older were significantly less likely to receive corticosteroids than those younger than 50 years (adjusted odds ratio 0·79 [95% CI 0·70â0·89], p=0·0001, for 70â79 years; 0·52 [0·46â0·58], p80 years), independent of patient demographics and illness severity. 84 (54·2%) of 155 pregnant women received corticosteroids. Rates of corticosteroid administration increased from 27·5% in the week before June 16, 2020, to 75â80% in January, 2021. INTERPRETATION: Implementation of corticosteroids into clinical practice in the UK for patients with COVID-19 has been successful, but not universal. Patients older than 70 years, independent of illness severity, chronic neurological disease, and dementia, were less likely to receive corticosteroids than those who were younger, as were pregnant women. This could reflect appropriate clinical decision making, but the possibility of inequitable access to life-saving care should be considered. FUNDING: UK National Institute for Health Research and UK Medical Research Council
Molecular mechanisms of cell death: recommendations of the Nomenclature Committee on Cell Death 2018.
Over the past decade, the Nomenclature Committee on Cell Death (NCCD) has formulated guidelines for the definition and interpretation of cell death from morphological, biochemical, and functional perspectives. Since the field continues to expand and novel mechanisms that orchestrate multiple cell death pathways are unveiled, we propose an updated classification of cell death subroutines focusing on mechanistic and essential (as opposed to correlative and dispensable) aspects of the process. As we provide molecularly oriented definitions of terms including intrinsic apoptosis, extrinsic apoptosis, mitochondrial permeability transition (MPT)-driven necrosis, necroptosis, ferroptosis, pyroptosis, parthanatos, entotic cell death, NETotic cell death, lysosome-dependent cell death, autophagy-dependent cell death, immunogenic cell death, cellular senescence, and mitotic catastrophe, we discuss the utility of neologisms that refer to highly specialized instances of these processes. The mission of the NCCD is to provide a widely accepted nomenclature on cell death in support of the continued development of the field
Emerging roles of T helper 17 and regulatory T cells in lung cancer progression and metastasis
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